//
// detail/impl/pipe_select_interrupter.ipp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef ASIO_DETAIL_IMPL_PIPE_SELECT_INTERRUPTER_IPP
#define ASIO_DETAIL_IMPL_PIPE_SELECT_INTERRUPTER_IPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include "asio/detail/config.hpp"

#if !defined(ASIO_WINDOWS_RUNTIME)
#if !defined(ASIO_WINDOWS)
#if !defined(__CYGWIN__)
#if !defined(__SYMBIAN32__)
#if !defined(ASIO_HAS_EVENTFD)

#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "asio/detail/pipe_select_interrupter.hpp"
#include "asio/detail/socket_types.hpp"
#include "asio/detail/throw_error.hpp"
#include "asio/error.hpp"

#include "asio/detail/push_options.hpp"

namespace asio {
    namespace detail {

        pipe_select_interrupter::pipe_select_interrupter() {
            open_descriptors();
        }

        void pipe_select_interrupter::open_descriptors() {
            int pipe_fds[2];
            if (pipe(pipe_fds) == 0) {
                read_descriptor_ = pipe_fds[0];
                ::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK);
                write_descriptor_ = pipe_fds[1];
                ::fcntl(write_descriptor_, F_SETFL, O_NONBLOCK);

#if defined(FD_CLOEXEC)
                ::fcntl(read_descriptor_, F_SETFD, FD_CLOEXEC);
                ::fcntl(write_descriptor_, F_SETFD, FD_CLOEXEC);
#endif // defined(FD_CLOEXEC)
            } else {
                asio::error_code ec(errno,
                                    asio::error::get_system_category());
                asio::detail::throw_error(ec, "pipe_select_interrupter");
            }
        }

        pipe_select_interrupter::~pipe_select_interrupter() {
            close_descriptors();
        }

        void pipe_select_interrupter::close_descriptors() {
            if (read_descriptor_ != -1)
                ::close(read_descriptor_);
            if (write_descriptor_ != -1)
                ::close(write_descriptor_);
        }

        void pipe_select_interrupter::recreate() {
            close_descriptors();

            write_descriptor_ = -1;
            read_descriptor_ = -1;

            open_descriptors();
        }

        void pipe_select_interrupter::interrupt() {
            char byte = 0;
            signed_size_type result = ::write(write_descriptor_, &byte, 1);
            (void) result;
        }

        bool pipe_select_interrupter::reset() {
            for (;;) {
                char data[1024];
                signed_size_type bytes_read = ::read(read_descriptor_, data, sizeof(data));
                if (bytes_read == sizeof(data))
                    continue;
                if (bytes_read > 0)
                    return true;
                if (bytes_read == 0)
                    return false;
                if (errno == EINTR)
                    continue;
                if (errno == EWOULDBLOCK || errno == EAGAIN)
                    return true;
                return false;
            }
        }

    } // namespace detail
} // namespace asio

#include "asio/detail/pop_options.hpp"

#endif // !defined(ASIO_HAS_EVENTFD)
#endif // !defined(__SYMBIAN32__)
#endif // !defined(__CYGWIN__)
#endif // !defined(ASIO_WINDOWS)
#endif // !defined(ASIO_WINDOWS_RUNTIME)

#endif // ASIO_DETAIL_IMPL_PIPE_SELECT_INTERRUPTER_IPP
